KWest - Embedded System Technologies

During the concept phase of a DSP system, the question often arises as to whether an Operating System is required or if a simple Interrupt -> Main Loop mechanism is sufficient. As the system becomes more complex and the number of system triggers grows, an Operating System is often unevitable. Apart from memory constraints, Context switching latency is an important consideration with DSPs, as large latencies cause a greater processing overhead that can only be reduced by increasing the Processing block size, which in turn boosts the memory requirements. Depending on your application, Kwest can provide services for: DSP/BIOS, VDK, Micrium OS, OSE, Integrity, Linux, and many more embedded RTOS.

Often a variety of audio interfaces exists in a system. For voice applications such as Bluetooth hands-free, a standard PCM-style interface is most commonly used. For stereo systems, often an I²S-style interface is used (e.g. Right-Justified or Left-Justified), for multi-channel audio such as 5.1, a TDM interface is used on PCB level. Newer approachs such as MediaLB from SMSC also try to embed control and packet data into these interfaces so as to offer more functionality between ICs. Externally, only a few approaches have succeeded in the mass market. For consumer applications, SP/DIF is commonly used, wheras in the automotive world MOST is the de-facto standard for digital audio distribution.

Data Streamlining
Data streamlining is short for „Having the right data and the right time at the right place“.DSPs can only achieve their maximum performance from internal multi-port memory. Hence data need to be retrieved from the interfaces, demultiplexed, and sorted and finally placed into internal memory so that they can be processed efficiently by the CPU. This sounds simpler than it is because data are derived from multiple asynchronous interfaces in different word widths, etc. Therefore the DSPs incorporate flexible and powerful DMA controllers that can reduce the CPU load significantly. KWest has integrated DMA managers into its Audio & Video Frameworks that make maximum use of these DMA engines.